Cloning and molecular characterization of putative invertase inhibitor genes and their possible contributions to cold-induced sweetening of potato tubers
Cloning and molecular characterization of putative invertase inhibitor genes and their possible contributions to cold-induced sweetening of potato tubers
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假定的蔗糖酶抑制剂基因的克隆和分子表征及其对马铃薯块茎冷诱导增甜的可能贡献
DOI：
10.1007/s00438-010-0554-3
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发表时间：
2010-09-01
影响因子：
3.1
通讯作者：
Liu, Jun
中科院分区：
文献类型：
--
作者：
Liu, Xun;Song, Botao;Liu, Jun
转化酶抑制剂（InvInh）与转化酶（Inv）相互作用，抑制其参与冷藏马铃薯块茎还原糖（RS）积累的活性。了解它们对RS积累的潜在贡献具有理论和实践意义，因为RS积累对马铃薯生产者和加工者来说都是一个代价高昂的采后问题。在这项研究中，四个基因与显着的序列同源性NtInvInhs从马铃薯和他们可能的贡献冷诱导甜味（CIS）的块茎一起进行了研究，StInv 1，一个酸性转化酶基因先前澄清对应于CIS。对不同CIS敏感性的6个马铃薯基因型的StInvInhs和StInv 1的转录本分析表明，StInvInh 2与冷藏块茎RS的增加呈负幂回归，而StInv 1与冷藏块茎RS的增加呈正线性回归。通过StInv 1/StInvInh 2计算的相对表达比率与RS积累进行了非常显著的相关性，表明StInv 1和StInvInh 2之间可能存在相互作用以响应CIS。双分子荧光互补可视化StInv 1和StInvInh 2A之间的相互作用，并与StInvInh 2B在洋葱表皮细胞和烟草BY-2细胞，并证明这两个抑制剂可能是StInvInh 2的异构体作为StInv 1的对应物。重组StInvInh 2B蛋白对可溶性酸性转化酶活性有明显的抑制作用。我们的研究结果强烈表明，StInv 1和StInvInh 2之间的相互作用可能发挥关键作用，通过在马铃薯块茎中的StInvInh 2的StInv 1的翻译后调节控制CIS，并将提供新的工具和资源，以提高马铃薯的CIS耐受性。
Invertase inhibitors (InvInh) interacted with invertases (Inv) and inhibited their activities involved in reducing sugars (RS) accumulation in cold-stored potato tubers. Understanding their potential contribution to RS accumulation is of both theoretical and practical importance because RS accumulation is a costly postharvest problem for both potato producers and processors. In this study, four genes with significant sequence homology to NtInvInhs were identified from potato and their possible contributions to cold-induced sweetening (CIS) of tubers were investigated together with StInv1, an acid invertase gene previously clarified corresponsive to CIS. Transcripts analysis of these StInvInhs and StInv1 among six potato genotypes with distinct CIS sensitivity indicated that StInvInh2 had a negative power regression to RS increase of the cold-stored tubers while a positive linear regression was obtained with StInv1. The relative expression ratio calculated by StInv1/StInvInh2 performed a very significant correlation to RS accumulation, suggesting a possible interaction between StInv1 and StInvInh2 in response to CIS. The bimolecular fluorescence complementation visualized the interaction between StInv1 and StInvInh2A and with StInvInh2B in both onion epidermal cells and tobacco BY-2 cells and demonstrated that these two inhibitors may be the isoforms of StInvInh2 as the counterparts of StInv1. The recombinant StInvInh2B protein inhibited the activities of soluble acid invertase indicating evidently its inhibitory properties. Our results strongly suggest that the interaction between StInv1 and StInvInh2 may play critical roles in controlling the CIS through posttranslational regulation of StInv1 by StInvInh2 in potato tubers and will provide novel tools and resources for improving CIS tolerance of potatoes.